Cooled turbine vane for turbines are generally known. The turbine vanes have a hollow sectional element at the end of which there is a transverse platform. An inset serving as a cooling baffle is accommodated in the hollow sectional element a certain distance from the inside of the outer wall and is provided with a large number of cooling openings. The coolant flows through the openings and hits the inside of the outer wall, thereby cooling it.
Compressor air is usually used as the coolant. Although the compressor air is cleaned by passing it through an air filter before it enters the compressor it still contains fine particles less than 10 μm in diameter. These fine particles, which may consist of dust, material particles or sticky compounds such as sulfur compounds, are often deposited on the inside of the baffle. In addition, agglomerates and corrosion products from these particles may be deposited on the openings of the inset, thereby reducing the cross-section of the opening. This leads to a reduction in the flow rate, and a much reduced cooling effect. This in turn can lead to thermal loads in the outer wall which may cause cracks to form or, in the case of laminated blades, to delamination of the blades.